Black pearlescent pigment with a metal layer

ABSTRACT

A pearlescent effect pigment having an opaque, dark or black color is disclosed. The black pearlescent pigment includes a platelet-shaped non-metal substrate, optionally an oxide layer, a template layer, and a metal layer. The pearlescent luster of the disclosed effect pigment is comparable to those of pure pearlescent effects. The disclosed method provides a cost-effective approach for the manufacturing of the disclosed effect pigment.

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

This application is a Division of application Ser. No. 12/628,779 filedon Dec. 1, 2009, which is incorporated by reference herein in itsentirety.

FIELD

This disclosure generally relates to pigments, and particularly, to thedesign of coated pigments and methods of producing the coated pigments.

BACKGROUND

Effect pigments having a sequence of interference layers applied to atransparent substrate are generally known as pearlescent pigments. Thetransparent substrate can include natural or synthetic mica, glassflakes, or metal oxides with a platelet shape. Mica, which isinexpensive, readily available and easy to cleave into smooth and thinplatelets, is commonly used. In addition, pigments based on mica arestable towards chemical or thermal treatment.

Various techniques have been developed to create color/luster effects.One approach to making these pigments is to coat a platelet substratewith a high refractive index metal oxide layer such as TiO₂, Fe₂O₃, andZr₂O₃ or with alternating layers of high and low refractivity asdescribed in U.S. Pat. No. 6,599,355, U.S. Pat. No. 6,500,251 and U.S.Pat. No. 6,648,957.

The use of a metal particle layer as a reflective layer also has beendisclosed. For example, U.S. Pat. No. 5,116,664 discloses atitanium-mica composite material comprising mica, a first coatingcomposed of titanium dioxide, and a second coating composed of powderparticles of at least one metal selected from the group consisting ofcobalt, nickel, copper, zinc, tin, gold and silver.

U.S. Pat. No. 6,794,037 is directed to a high chroma effect materialcomprising a platelet substrate encapsulated with a layer of silver aslight reflective layer, then a spacer layer of metal oxide, nitride,fluoride, and finally an iron oxide layer.

U.S. Pat. No. 6,440,208 discloses a color effect material wherein theplatelet substrate is coated first with a light reflective layerselected from the group consisting of copper, zinc, an alloy of copper,and an alloy of zinc, then with a second layer of silicon dioxide ormagnesium fluoride, and then a third layer that is selectivelytransparent to light.

U.S. Pat. No. 6,325,847 describes precious metal color effect materialswhere a platelet substrate is encapsulated with a reflective preciousmetal layer, a second layer of silicon dioxide or magnesium fluoride andalso with a selective transparent third layer.

U.S. Pat. No. 7,226,503 relates to an effect pigment comprising a glassflake with a thickness of ≦1.0 μm coated with one or more layers ofmetal oxides, metal suboxides, metal oxyhalides and metal fluorides etc.

U.S. Pat. No. 5,308,394 discloses a pigment that includes alight-transparent ceramic scaly substrate, a thin compound layer coatedon a surface of the substrate, a rutile layer titanium dioxide layerformed on a surface of the substrate coated with a tin compound, a metalcompound layer coated on a surface of the titanium dioxide layer, themetal compound being at least one selected from the group consisting ofBi, Sb, As, Cd, Mn, Pb and Cr, and metallic glossy dots formed on thesurfaces in a scattering manner.

U.S. Pat. No. 6,800,125 discloses an oxide metallic color effectmaterial comprising a platelet-shaped substrate encapsulated with alight reflective silver layer, followed by a layer of iron oxide.

U.S. Pat. No. 6,582,764 discloses a hybrid inorganic/organic coloreffect material that includes a platelet substrate core coated with afirst layer which acts as a reflector to light directed thereon. Thefirst layer can include an alloy of copper and zinc, an alloy ofaluminum and copper, an alloy of aluminum and zinc, copper or zinc. Thematerial further includes a second organic polymer layer, and aselectively transparent third layer.

U.S. Pat. No. 6,821,333 discloses a color effect material comprising aplatelet-shaped substrate encapsulated with a highly reflective layer ofmetal selected from silver, gold, platinum, palladium, rhodium,ruthenium etc, a spacer layer of metal oxide, nitride, fluoride orcarbide or polymer, and an outer layer selected from metals or metaloxides.

U.S. Pat. No. 6,582,764 is directed to a hybrid/organic color effectmaterial that includes a platelet-shaped substrate encapsulated withthree layers. The first layer includes either an alloy of copper andzinc, an alloy of aluminum and copper, or an alloy of aluminum and zinc.The second layer is an organic layer and encapsulates the first layer.The third layer is a selectively transparent layer.

All these pearlescent pigments have an interference color effect and aluster effect. However, the hiding power of such pearlescent pigments isso small that an underlayer cannot be sufficiently covered. Thus, thepigments are either transparent or semi-transparent. Moreover, when suchpigments are subjected to a colorimetric appraisal using the CIE labcolor space system, the pigments do not exhibit a black color effectwhile maintaining a pearlescent luster effect.

CIElab values are measured with a Multi-angle Spectrophotometer atdifferent angles of 15°, 25°, 45°, 75° and 110°. The reported colorcoordinates (L, a*, b*) are related to lightness (L) and color (a* andb*). The a* is the red/green content and b* is the blue/yellow content.If a pigment has a low L value with a* and b* values close to zero at acertain angle, this means that the pigment is black at that angle.Further, if the same pigment has a very high lightness (L) value atdifferent angles, this means that the pigment has high light travelproperty.

Blackness (also called Jetness) can be evaluated using a color dependentblack value Mc. Mc is the best jetness parameters so far, and correlateswell with the human perception of increased jetness. As Mc increases,the jetness of the masstone increases. Mc is calculated from tristimulusvalue of illuminating light source (Xn, Yn, Zn) and the reflected lightof sample (X, Y, Z), based on the following equations:

L=116(Y/Yn)^(1/3)−16

a*=500[(X/Xn)^(1/3)−(Y/Yn)^(1/3)]

b*=200[(Y/Yn)^(1/3)−(Z/Zn)^(1/3)]

Mc=100[log(Xn/X)−log(Zn/Z)+log(Yn/Y)].

An Mc value of 150 or higher is considered highly jet.

Pigments with black color especially at flop angle with high lighttravel exhibiting high jetness have been widely demanded. Althoughcarbon can be blended so as to create a black effect, such an additiondecreases the pearlescent luster effect significantly.

Efforts have been made to obtain dark color effects. U.S. Pat. No.5,753,024 for example discloses grey pigments that include a substratecoated with tin oxide and at least one further metal oxide and furthercoated with organic colloids that are calcined at temperatures of900-1100° C. Silver-grey semi-transparent color pigments having micacoated with titania, ferric oxide and tin oxide are known. Black olivesemi-transparent pigments that are based on mica and coated with cobaltiron oxide and cobalt oxide are also known. Such pigments have a brownundertone color. However, the above pigments have an undesirableundertone and do not have good hiding power.

SUMMARY

A pearlescent effect pigment having an opaque, dark or black color isdisclosed. The pearlescent luster of the disclosed effect pigment iscomparable to those of pure pearlescent effects. The disclosed methodprovides a cost-effective approach for the manufacturing of thedisclosed effect pigment.

In one embodiment, the dark or black pearlescent pigment includes aplatelet-shaped non-metallic reflector core, an oxide layer, a templatelayer, and a metal layer. In one example, the template layer permits asubstantially uniform and smooth coated surface to be formed. In oneimplementation, the template layer includes an organic layer. In oneinstance, the template layer is an organic polymer layer grown viaAtomic Transfer Radical Polymerization (ATRP). In another instance, thetemplate layer is an organic monolayer.

In another example, the template layer is coated with a metal layer. Themetal layer is substantially continuous. In one implementation, themetal layer is formed by electroless deposition. In this instance, thetemplate layer includes amine groups that contribute to the formation ofhigh density catalyzing sites. In one example, the high densitycatalyzing sites permit the metal layer to be uniform and continuous soas to create opacity. In one implementation, the amine groups providemetal-ion complexing sites for sensitizing the substrate. Themetal-ion-sensitized surface of the substrate provides strong absorptionof the catalyst layer to the substrate during the activatingpretreatment for the electroless deposition.

In one embodiment of the method of producing the dark or blackpearlescent pigment, the method includes forming a catalyst layerin-situ on the surface of a substrate and depositing a metal layer onthe catalyst layer. In one example, depositing a metal layer involveselectroless deposition, wherein an activation of the sensitizedsubstrate and reduction of the metal salts are a one-step reaction.

The products of the present disclosure are useful in automotive,cosmetics, industrial or any other application where pearlescent pigmentcan be used.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B illustrate embodiments of the disclosed coated pigment.

FIGS. 2A and 2B show the SEM image of the effect pigment surface at highmagnification (100K). FIG. 2A is the image of white pearlescent pigmentsurface before coating. FIG. 2B is the surface after multilayer coating.

FIG. 3 shows Auger analysis indicating that the Ag layer is continuous.

DETAILED DESCRIPTION

A coated pigment including a non-metal substrate, an oxide layer, atemplate layer, and a metal layer and a method of producing the coatedpigment are described. The disclosed coated pigment has a dark or blackundertone and has an outstanding hiding property.

With reference to FIG. 1A, a coated pigment 10 includes a substrate 1.In one example, the substrate 1 can be an encapsulatable platelet. Thesize of the encapsulatable platelet 1 can have any size that is suitablefor forming an effect pigment. In one implementation, the encapsulatableplatelet 1 has a diameter in the range of 5 μm to 700 μm, and athickness of 5 nm to 500 nm. The diameter and thickness can be measuredusing, for example, Field Emission Scanning Electron Microscopy (FESEM).In this instance, the diameter is measured as viewed in cross-sectionaltop view of the platelet, and the thickness is measured as viewed incross-sectional side view of the platelet.

In one example, the substrate 1 is a non-metal substrate. The term“metal” herein means that the oxidation state of the element metalpresent in the substrate is zero. The term “non-metal” herein means thatthe oxidation state of the element present in the substrate is otherthan zero.

In one instance, the substrate 1 can be formed of any material that issuitable for forming an effect pigment, including, but not limited to,glass, silicon oxide, and titanium dioxide-coated mica. In anotherinstance, the substrate 1 includes an oxide layer, which can include,but is not limited to, metal oxides such as SiO₂, TiO₂ and ZrO₂.

The substrate 1 is coated with a first layer 2. In one example, thefirst layer 2 is an oxide layer. The oxide layer 2 can include, but isnot limited to, metal oxides such as SiO₂, TiO₂ and ZrO₂. In oneimplementation, the oxide layer 2 is part of a white pearlescent, whichis mica that is coated with TiO₂. In one example, the thickness of thefirst layer 2 has a range from a few nm to tens of nm.

The first layer 2 is further coated with a second layer 3. In oneexample, the second layer 3 is a template layer. In one instance, thetemplate layer 3 is an organic monolayer. The term “organic monolayer”herein means a layer that includes molecules with an organic chain. Inone example, the organic monolayer 3 includes an aminosilane monolayerand is provided by silanization. Examples of the aminosilane that can beutilized include gamma-aminopropyl trimethoxysilane, γ-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane,gamma-(2-aminoethyl)aminopropylmethyldimethoxysilane, and the like whichcontains amino group in the chain or at the end of the chain. The aminogroup can be a primary amine, secondary amine or tertiary amine. In oneinstance, the amount of the aminosilane included is in a range of 0.1 to20% by weight based on the weight of the starting substrate. In anotherinstance, the amount of the aminosilane included is in a range of 1 to50% by weight based on the weight of the starting substrate. In yetanother instance, the amount of the aminosilane included is in a rangeof 1 to 20% by weight based on the weight of the starting substrate. Inyet another instance, the amount of the aminosilane included is in arange of 1 to 10% by weight based on the weight of the startingsubstrate.

In another embodiment, the template layer 3 is an organic polymer layer.The organic polymer layer 3 can include polystyrene (PS),polymethylmetacrylate (PMMA), polymethacrylate (PMA), 2-hydroxy ethylmethacrylate, glycidyl methacrylate, and/or dimethylamino ethylmethacrylate.

In one example, the organic polymer layer 3 is formed by immobilizinginitiator molecules onto the surface of the first layer 2. In oneimplementation, the initiator includes a surface active group and aninitiator moiety and the surface of the first layer 2 includes afunctional group. The initiator molecule is immobilized by reacting thesurface active group of the initiator molecule with the functional groupon the surface of the first layer 2. Then, the immobilized initiatormolecule is reacted with one or more polymerizable monomers so thatmonomers are added to the initiator moiety and form a polymer chainattached to the surface of the first layer 2. In one instance, theorganic polymer layer 3 is grown via atomic transfer radicalpolymerization (ATRP).

In yet another example, the polymer chains within the organic polymerlayer 3 are substantially uniform in length such that the organicpolymer layer 3 has a substantially uniform thickness. In one instance,the organic polymer layer 3 has a substantially uniform thickness asviewed by Transmission Electron Microscopy (TEM). In this instance, thethickness of the organic polymer layer 3 can be in a range from a fewnanometers to 100 nm and have a standard deviation of less than 15% ofthe average thickness as measured using a transmission electronmicroscope at a magnification between ×20,000 and ×100,000.

In another implementation, the thickness of the organic polymer layer 3can be increased or decreased by increasing or decreasing the reactiontime, respectively. In yet another implementation, the thickness of theorganic polymer layer 3 can be increased or decreased by increasing ordecreasing the reaction temperature, respectively. In still yet anotherimplementation, the thickness of the organic polymer layer 3 can beincreased or decreased by increasing or decreasing the monomerconcentration, respectively.

In yet another example, the template layer 3 includes an amino group.The amino group can be a primary amine or secondary amine. In the casewhere the template layer 3 is the organic polymer layer, the amino groupis provided by growing a hydrophilic coating layer on the polymer chainends after a desired length of the initial polymer chains is achieved.In one example, the hydrophilic layer includes poly(dimethylaminoethylmethacrylate).

With reference to FIG. 1B, in another embodiment, a coated pigment 20does not include an oxide layer. In one example, the substrate 1 of thecoated pigment 20 includes hydroxyl groups. In this instance, thesubstrate 1 is directly coated with the second layer 3. In oneimplementation, the substrate 1 is a glass flake.

With reference to FIGS. 1A and 1B, the second layer 3 is further coatedwith a third layer 4. In one embodiment, the third layer 4 is a metallayer. The metal layer 4 can include silver, copper or nickel. In oneinstance, Auger electron microscopy (AES) mapping can be used todetermine the coverage of the metal layer 4. In one example, thecoverage of the metal layer 4 is substantially continuous, such that anAES map for a metal within metal layer 4 does not reveal discontinuityin the coverage of the metal layer 4 at a magnification of ×7500 and ascanned area of 15 μm×15 μm using 256 pixel×256 pixel density. Here, theterm “substantially continuous” means that Auger Electron Microscopy atthe given magnification for the scanned area of ×7500 and 15 μm×15 μmusing 256 pixel×256 pixel density, respectively, cannot resolvediscontinuity of the metal layer 4 such that discrete metal particlesare not observed.

The metal layer 4 can be formed on the second layer 3 by anysurface-covering techniques suitable for depositing a metal on thesecond layer 3. In one example, the metal layer 4 is plated byelectroless deposition.

Generally, electroless metal deposition involves the use of a chemicalreducing agent to plate a metal from a solution. The electrolessdeposition technique allows one to control the thickness of the coating.One useful plating technique of this type is to arrange the chemistrysuch that the kinetics of homogeneous electron transfer from thereducing agent to the metal ion are slow within the electroless-platingbath so as to prevent the metal ion from being reduced in the bulksolution. A catalyst that accelerates the rate of metal ion reduction isthen applied to the surface to be coated. In this way, metal ion isreduced only at the surface, and the surface becomes coated with thedesired metal. The metal can be deposited from reduction of aqueoussalts of the metals.

In one example, the metal layer 4 is formed by reducing a water-solublemetallic salt. The metallic salt that can be utilized include silversulfates, silver hydrochlorides, silver nitrates, silver carbonatesetc., copper sulfate, copper hydrochlorides, copper nitrates, coppercarbonates etc., and nickel sulfate, nickel hydrochlorides, nickelnitrates, nickel carbonates etc.

In yet another example, before the metal layer 4 is formed on the secondlayer 3 by electroless deposition with water-soluble metallic salt, thesurface of the second layer 3 is activated by a pretreatment. In oneinstance, the pretreatment is a sensitizing-activating treatment thatforms a catalyst layer on the surface of the second layer.

In one implementation, a sensitizing solution including a metal ion isutilized. In one example, the metal ion utilized is Sn(II). In thisinstance, the amine groups included within the second layer 3 act as“molecular anchors” that bond the Sn(II) to the surface of the secondlayer 3, thereby sensitizing the surface of the second layer 3. Once thesurface of the second layer 3 is sensitized, the surface is activated byimmersion in an aqueous solution of metallic salt containing Ag, Pd orPt. This causes a redox reaction in which the surface is coated withdiscrete, nanoscopic Ag, Pd or Pt particles. These particles providecatalytic sites and together form a catalyst layer including Ag, Pd orPt nuclei. Thereafter, the metal layer 4 can be formed on the surface ofthis catalyst layer by electroless plating. In particular, as describedabove, when the catalyst layer is exposed to an electroless platingsolution, a reducing agent in the plating solution is oxidized on thesurface of the catalyst layer due to catalytic activity. Metallic saltsin the electroless plating solution are then reduced by the emittedelectrons, the metal is deposited on the surface of the catalyst layeronly, and the continuous metal layer 4 is formed.

In one example, forming the catalyst layer and depositing the metallayer are a one-step reaction.

In one embodiment, the disclosed coated pigment has a dark or blackcolor such that when the CIElab values of the disclosed coated pigmentare measured using a X-rite MA68II Multi-angle Spectrophotometer atdifferent angles of 15°, 25°, 45°, 75°, 110°, the a* and b* values areclose to zero at the measured angles. In one instance, the a* and b*values are 0.26 and −0.06, respectively, at 110° and 1.87 and −3.17,respectively, at 15°.

In another embodiment, the disclosed coated pigment exhibits extremelight travel such that when the CIElab values of the disclosed coatedpigment are measured using a X-rite MA68II Multi-angle Spectrophotometerat different angles of 15°, 25°, 45°, 75°, 110°, the lightness (L value)is very high at the measured angles. In one instance, the L value is upto 99.62 at 15° angle and the L value is 5.17 at an angle of 110°.

In yet another embodiment, the disclosed coated pigment has high jetnesssuch that when the disclosed coated pigment is evaluated using a colordependent black value Mc, the Mc value is over 150 at angles of 75° and110°.

EXAMPLES Example 1 Monolayer as Template Layer Attachment

20 g of TiO₂-coated (anatase) mica with a particle size of 10-60 μm(D50=19 μm according to Malvern particle size analysis) were dispersedin 500 mL glycol ether PM with stirring and after 5 minutes, 1% ofγ-aminopropyl trimethoxysilane on TiO₂-coated mica by weight was addedinto the dispersion and stir for 10 minutes, then 1% of water was addedas catalyst with stirring at room temperature. After two hours, theslurry was filtered and washed with glycol ether PM initially followedby water.

Example 2 Monolayer as Template Layer Attachment

Example 1 was repeated except that 10% ofN-(2-aminoethyl)-3-minopropyltrimethoxysilane and 10% of water wereadded.

Example 3 Polymer Layer as Template Layer Attachment

Step 1—Functionalize TiO₂-Coated Mica with ATRP Initiator

The reaction was carried out in the fumehood, using a 500 mL roundbottom flask equipped with a magnetic stirring bar and a condenser.

The following chemicals were added to the reaction flask:

37.5 g TiO₂-coated mica   0.3 mL3-(trimethoxysilylpropyl)-2-bromo-2-methylpropionate   300 mL Toluene.The reaction mixture was heated and was kept under reflux for 18 hours.Once the reaction time was complete, the mixture was cooled down to roomtemperature. The flakes were vacuum filtered. Three washes of toluene(200 mL) were applied.

Step 2—Surface-Initiated Polymerization of Styrene andDiemthylaminoethyl Methacrylate

The following reaction was carried out in the fumehood, using a 100 mLreaction flask equipped with a mechanical stirrer and a heating mantle.

To the reaction flask, a stir bar and the following reagents were added:

CuBr 0.25 g Styrene 40 mL TiO2-coated mica from step 1 6.38 g(containing 4 g of NV) Toluene 40 mL.

The flask was sealed with a rubber septum and degassed with N₂ and thenthe solution was heated to 60° C. In a separated flask,pentamethyldiethylenetriamine (PMDETA) was degassed with nitrogen for 30min. Then, 0.37 mL of degassed PMDETA was transferred to the reactionflask with an N₂ purged syringe. The solution was kept at 60° C. for 1hour before 40 mL of reaction mixture was withdrawn from the reactionmask. After 1.5 hours of polymerization, 37 mL of degasseddimethylaminoethyl methacrylate was transferred to the reaction flaskwith N₂ purged syringe. The reaction mixture was kept at 60° C. for anadditional 1 hour before the reaction was stopped by cooling thereaction flask to room temperature. The pigments were separated from thereaction mixture via centrifugation.

Example 4 Silver Layer Coating on White Pearlescent Pigments Step1—Monolayer as Template Layer Attachment

Same as Example 1.

Step 2—Pretreatment of Template Layer-Coated Pigment

Template layer-attached white pearlescent pigments from step 1 wasdispersed in a solution of 2.5 g SnCl₂ and 2.5 mL HCl in 500 mL waterand kept stirring for 20 min pretreatment, and then filtered.

Step 3—Silver Layer Coating

The following solutions were used:

Solution A—5 g AgNO₃ was dissolved in 50 mL water, NH₄OH 10 mL wasadded, then more water was added to make a total volume of 200 mL;

Solution B—7.5 g of sodium potassium tartrate was dissolved in 200 mLwater.

The filtered pigment from step 2 was dispersed into 200 mL water andtransferred to 2 L reactor equipped with stirring and temperaturecontrol. The slurry was stirred at 350 rpm. To the slurry, solution Awas first added and was allowed to sit for 5 minutes. A light browncolor was observed. Then, solution B was added and stirred at 350 rpm.The temperature was set at 50° C. first for 30 min, then increased to60° C. The total reaction time was 2.5 hours. Then the slurry was cooleddown to room temperature, filtered, and thoroughly washed with water,and then washed with isopropyl alcohol once and was air dried. Theresulting powder was black.

Example 5 Step 1—Monolayer as Template Layer Attachment

Similar to example 1, except 50 g of white pearlescent pigments wasdispersed in 1000 mL glycol ether PM.

Step 2—Pretreatment of Template Layer-Coated Pigment

Template layer-attached white pearlescent pigments from step 1 wasdispersed in a solution of 6.25 g SnCl₂ and 6.25 mL HCl in 1000 mL waterand stirred for a 30 min pretreatment, and then filtered and washed withwater.

Step 3—Silver Coating

The following solutions were used:

Solution A—12.5 g AgNO₃ was dissolved in 50 mL water, NH₄OH 18.75 mL wasadded, then more water was added to make a total volume of 200 mL

Solution B—18.75 g of sodium potassium tartrate was dissolved in 300 mLwater

The filtered pigment from step 2 was dispersed into 500 mL water andtransferred to a 2 L reactor equipped with stirring and temperaturecontrol. The slurry was stirred at 350 rpm. To the slurry, solution Awas first added and allowed to sit for 5 minutes. Once a light browncolor was observed, solution B was added and was stirred at 350 rpm. Thetemperature was set at 30° C. first, then gradually increased by 10° C.every 20 min until reaching 60° C. The total reaction time was 2.5hours. Then, the slurry was cooled down to room temperature, filtered,and thoroughly washed with water, and then washed with isopropyl alcoholonce and air dried. The resulting powder was black.

Example 6

2 g of polymer layer attached white pearlescent pigments from example 3was dispersed into a solution of 0.5 g SnCl₂ and 1.0 mL trifluoroaceticacid in 200 mL water and stirred for 20 min as a pretreatment, and thenfiltered and washed with water.

The filtered substrate was dispersed into 200 mL water and transferredto 1 L round bottom flask equipped with a magnetic stirring bar and acondenser. While the slurry was stirring, two solutions were made:solution A—0.5 g AgNO₃ dissolved in 20 mL water, NH₄OH 1.0 mL was added,then more water was added to make a total volume of 100 mL; solutionB—3.0 g of sodium potassium tartrate was dissolved in 100 mL water.

To the above slurry, solution A was first added and allowed to sit for 5minutes. Once a light brown color was observed, solution B was added andstirred. The temperature was set at 60° C. The total reaction time was2.5 hours. After the reaction was complete, the slurry was cooled downto room temperature, filtered, and thoroughly washed with water, andthen washed with isopropyl alcohol once and air dried. The resultingpowder was black.

Example 7 Evaluation of the Black Pigments Nitrocellulose Ink Drawdown

To evaluate the coloristic of the pigments obtained, in each case 1 g ofpigment sample was mixed with nitrocellulose in isopropyl acetate havinga solid content 20% by weight and dispersed for 30 second in theSpeedmixer (DAC 150 FVZ-K) from FlackTeck Inc. A drawdown bar (#14) wasused to prepare drawdowns of the pigmented varnish on a piece of blackand white ink cardboard. After the film had dried at room temperature,CIELab values were measured with a X-rite MA68II Multi-angleSpectrophotometer at an angle difference of 15°, 25°, 45°, 75°, 110°.The reported color coordinates (L, a*, b*) related to the standardilluminate D65 and a viewing angle of 10°. L is the lightness, a* is thered/green content and b* is the blue/yellow content. The measurementswere carried out on single drawdowns over a white background as shown inTable 1.

TABLE 1 L a* b* Sample from example 4 (Measuring angle) 15° 91.76 1.87−3.17 25° 61.49 1.19 −1.98 45° 25.95 1.11 −0.93 75° 9.89 0.63 −0.33110°  6.96 0.26 −0.06 Sample from example 5 (Measuring angle) 15° 99.623.29 1.17 25° 62.01 2.13 1.28 45° 22.67 1.83 1.14 75° 7.95 1.7 1.51110°  5.17 1.17 1.34The Mc values calculated from the above measurement are shown as inTable 2 below.

TABLE 2 Mc Sample from example 4 (Measuring angle) 15° 11.28 25° 54.0245° 133.39 75° 195.62 110°  210.90 Sample from example 5 (Measuringangle) 15° −1.20 25° 49.62 45° 139.46 75° 198.56 110°  215.09

Example 8 Evaluation of the Black Pigments Refinish Paint System

To evaluate the resulting black pearls from example 4 in a paint system,a solvent-borne acrylic system for both base-coat and clear-coat wasused. 8 g of dry black pearls was dispersed in 92 g of base-coat acrylicresin varnish, and then mixed with the same volume of solvent blendthinner. The resulting paint was filtered and sprayed with Siphon onclear ABS plastic chips. The sprayed chips were baked in the oven at150° F. for 20 minutes. For the following clear coat, three parts ofclear-coat acrylic resin varnish was mixed with one part of clear-coatdi-isocyanate hardener and one part of solvent blend thinner. Then theresulting clear coat was sprayed on the plastic chips, and baked in theoven at 170° F. for 30 minutes. The sprayed and baked coating lookedblack with very good hiding. Same as in example 7, the CIELab values ofchips were measured with a X-rite MA68II Multi-angle Spectrophotometerat an angle difference of 15°, 25°, 45°, 75°, 110° (in Table 3).

TABLE 3 Sample from example 4 (Measuring angle) L a* b* 15° 75.65 2.79−2.43 25° 51.78 1.65 −1.52 45° 20.00 1.00 −1.00 75° 6.88 0.40 −0.71110°  4.50 0.17 −0.34The correspondent Mc values are shown in Table 4 below.

TABLE 4 Sample from example 4 (Measuring angle) Mc 15° 31.77 25° 70.9645° 153.69 75° 213.30 110°  226.81

SEM Image Analysis

Samples were mounted on an aluminum stub via a piece of double-sidedconductive carbon tape using a clean laboratory spatula. The extra powerwas purged away by nitrogen before introduction into the analyticalchamber of SEM. Clean tweezers and gloves were used for all samplehandling. The samples were placed in the analytical chamber which wasthen evacuated to <1×10⁻⁵ torr. All microscopy was done at a workingdistance of 15 mm. FIG. 2A is the SEM image of the white pearlescentpigment surface before coating and FIG. 2B is the SEM image of thesurface after multilayer coating.

Auger Electron Microscopy (AES) Mapping

Suspensions were made from dry powder and cast onto clear Si foranalysis. FIG. 3 shows the survey scan of silver of the depositedsample.

While the disclosed coated pigments and methods have been described inconjunction with a preferred embodiment, it will be apparent to oneskilled in the art that other objects and refinements of the disclosedcoated pigments and methods may be made within the purview and scope ofthe disclosure.

The disclosure, in its various aspects and disclosed forms, is welladapted to the attainment of the stated objects and advantages ofothers. The disclosed details are not to be taken as limitations on theclaims.

1. A method of producing the coated pigment comprising a substrate, thesubstrate being non-metal; a template layer, the template layer being anorganic monolayer or an organic polymer layer; and a metal layer; themethod comprising: forming a catalyst layer in-situ on the surface ofthe substrate; and depositing the metal layer on the catalyst layer. 2.The method of claim 1, wherein depositing the metal layer includesdepositing a metal onto the surface of the substrate with electrolessdeposition.
 3. The method of claim 1, wherein forming the catalyst layerand depositing the metal layer are a one-step reaction.